Method for separating metal mixtures into their different components



Feb 23, 1932;. J. KOHLMEYER METAL MIXTURES INTO THEIR DIFFERENT COIPONENTS METHOD FOR smmnzvrme Filed llay 29, 1928 2 She ets-Sheet l Feb. 23, 1932. J, KQHL'MEYER 1,846,738

HBTIIOD FOR SEPARATING IETAL MIXTURES INTO THEIR DIFFERENT COIPONENTS Filed May 29, 1928 2 Sheets-Sheet 2 m D g;

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atented Feb. 23, 1932 Aren't.

OFFICE J1 U$TUS KOHLMEYER, F BERLIN -CH.ARLOTTENlEiURG, GERMAN Y, ASSIGNOR TO AMERI- CAIN LURGI CORPORATION, OF

NEW YORK, N. Y., A CORPORATION OF NEW YORK ETE'LHOD FOR SEPARATING METAL MIXTURES INTO THEIR DIFFERENT COMPONENTS Application filed May 29, 19 Serial No. 281,537, and in Germany May 31, 1927.

This invention relates to a. method for separating metal mixtures into their dlfferent components by volatilization of at least one component'of the metal mixture used as starting material.

A. method which in the last ten years has been used toa great extentfin metallurgical engineering for separating metals such as copper and zinc, copper and tin in old materials, copper and lead in speiss, black copper and the like consists in blowing these substances in converters. The converters used for this purpose are vertical or horizontal cylinders from sheet metal, provided with a lining of refractory material, carrying at one side nozzles for introducing and distributing air or other gases. Compressed air is blown in through these nozzles, thus Whirling the metal and combustingthe volatile constituents, which are in part vola-tilized. The converters are only tiltable, especially for filling or emptying purposes.

This blowing of metallur ical products has several disadvantages. i e part of the converter lining, provided with openings for the nozzles is subjected to an extreme stress and in consequence thereof is easily destroyed, thus making it often necessary, to renew the lining zone carryingthe nozzles. As the outlet openings of the nozzles interrupt the lining of the converter and especially the lower part of the lining, upon which is resting a great part of the upper lining, the renewal of this lower part of the lining makes it generally necessary, to renew a great piece of the whole lining.

the anain reactions take place and the greatest heat is developed, the lining is weakest due to the outlet openings of the nozzles. Another important disadvantage of the blowing in converters and of the refining in stationary flame furnaces is to be found in the poor metallurgical result of these processes. By the manner,'in which the compressed air enters the bath of molten metal, I also a considerabletpart of the non volatile compounds are oxidized together with the volatile components of. the raw material, so that at the end of the process there is formed for example when blowing copper-alloys,- be

At those places, where sides metallic copper a considerable amount of copper slag, which has to be reduced to metal in special shaft furnaces. The slags obtained by blowing contain up to 35% copper; the slags obtained when refining copper in stationary flame furnaces contain even up to 50% copper.

All these disadvantages are avoided, when working according to the present invention, which consists in keeping the molten bath of the raw material to be blown covered with a layer of fuel during the blowing process. It is preferable to carry this method out in a drum furnace, rotatable around 360 and provided with an arrangement for blowing in air during the rotation.

In the annexed drawings, a. furnace which is adapted for the purpose in question is illustrated by way of example.

1F ig. 1 shows the furnace in section,

1* ig. 2 a view of the funace at the burner side,

Fig. 3 the twyer box in section,

Fig. 4 a detail of a part of the twyer box and Fig. 5 a vertical section through Fig. 4:.

A is' the rotatable drum furnace arranged on rollers B and rotatable about 360. The length of this furnace is about the same as the diameter of its circular cross section. The furnace A consists of an outer casing m of sheet metal, provided with a lining a of refractory material. The front side of the furnace carries an opening 0, into which one or several movable burners I: enter, whereas the waste gases leave the furnace also by, this opening 0 through the tubeZ. At the opposite side of the furnace an opening 71. for charging purposes is arranged, closed by a cover during the working of the furnace. On that side also the tapping opening 'p is arranged. At the burnei side, for example 20 nozzles b for introducing air are arranged. Each nozzle 7) has a nozzle casing c, which is connected by a tube or metal-hose e with the ring shaped casing d foradmission of the air. This casing d is divided by special walls into several air-tight chambers f for eachnozzle. The'tightening towards the outside is done by a ring-shaped packing plate 9 (Figs.

i manner,

4 and 5) in a stufiing box. Whereas the ring casing d rotates together with the furnace A (Figs. 1, 4 and 5) the ring 9 is stationary and connected with the main air tube h (Fig. 5). The tube It enters a sector-shaped twyer box 5 (Fig. i) which is also stationary with the packing ring g. The ring 9 has at 9 (Fig. 5) an opening, which extends over the whole twyer box 2'. It is thus provided, that compressed air only enters through the nozzles which just pass the opening 9 during the rotation. This arrangement of the nozzles makes it possible, that the nozzles are not continuously touched by the hot metal bath, but are always removed during the rotation from the bath and are cooled while they are above the surface of the metal bath.

The device Works as follows:

The material in the furnace is either charged into the furnace in liquid form or in solid form and is then melted in the furnace by the burners is below the waste gas exit tube Z. Care must be taken at first that only such an amount of metal is introduced, that the level of the metal when molten only reaches to the lower wall of the lowest nozzle, as otherwise the nozzles would be filled with liquid material as long as compressed air is not yet introduced. Then when the level of the bath comes up to the nozzle openings, the burner is stopped and compressed air introduced through the nozzles. Then further solid metal may be added to the metal bath in the furnace. The surface of the bath is during the blowing kept covered with coke or similar granular fuel in such a that the fuel forms a uniform and complete cover above the level of the bath. Further fuel has to be added in such amounts, as corresponds to the use of the fuel.

The metals or metalloids of the bath are volatilized one after the other in correspondence to their capability of being oxidized by the oxygen of the air blown in. The nonvolatile oxides form a slag, which is reduced again by the intimate contact with the coke. When the reduced substances are volatile met als, they are volatilized and oxidized again in the waste gases, from which they may be recovered as oxidic dust or the like.

If all the volatile constituents are removed from the metal bath, the latter may in known manner be refined and tapped through the opening 19 of the furnace. 7

If sulphur compounds such as copper, which do not contain recoverable volatile constituents, are to, be blown, it is naturally not necessary, to cover the bath with a layer of reducing fuel. If however mixed sulphur compounds such as lead containing coppermatte are to be blown, a layer of fuel will very much help the volatilization of the lead.

In the appended claims, by the term volatile metals I mean zinc, lead and tin.

I claim:

1. A method for separating volatile from non-volatile metals or metalloids which comprises blowing in a rotary furnace with an oxygen-containing gas a fused bath containing non-volatile metals and an element or elements of the group comprising a volatile metal and a metalloid said bath being covered with a layer of reducing agents during the entire process.

2. The process which comprises blowing in a rotary furnace with an oxygen-containinggas, a fused bath comprising copper and a metal or metals of the group consisting of zinc, tin and lead, said bath being covered with a layer of reducing agents during the entire process.

8. The process which comprises blowing in a rotary furnace with an oxygen-containing gas, a fused bath comprising copper matte, said bath being covered with a layer of reducing agents during the entire process.

l. The process which comprises blowing in a rotary furnace with an oxygen-containing gas, a fused bath comprising copper-leadmatte, said bath being covered with a layer of reducing agents during the entire process. In testimony whereof I affix my signature.

JUSTUS KOHLMEYER. 

